MALLORY DOLORFINO, LUKE MARTIN, ZACHARY SLONIM, YUXUAN SUN, YONG YANG
{"title":"ON THE CHARACTERISATION OF ALTERNATING GROUPS BY CODEGREES","authors":"MALLORY DOLORFINO, LUKE MARTIN, ZACHARY SLONIM, YUXUAN SUN, YONG YANG","doi":"10.1017/s0004972723001429","DOIUrl":null,"url":null,"abstract":"Let <jats:italic>G</jats:italic> be a finite group and <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline1.png\" /> <jats:tex-math> $\\mathrm {Irr}(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> the set of all irreducible complex characters of <jats:italic>G</jats:italic>. Define the codegree of <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline2.png\" /> <jats:tex-math> $\\chi \\in \\mathrm {Irr}(G)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> as <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline3.png\" /> <jats:tex-math> $\\mathrm {cod}(\\chi ):={|G:\\mathrm {ker}(\\chi ) |}/{\\chi (1)}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> and let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline4.png\" /> <jats:tex-math> $\\mathrm {cod}(G):=\\{\\mathrm {cod}(\\chi ) \\mid \\chi \\in \\mathrm {Irr}(G)\\}$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be the codegree set of <jats:italic>G</jats:italic>. Let <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline5.png\" /> <jats:tex-math> $\\mathrm {A}_n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> be an alternating group of degree <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline6.png\" /> <jats:tex-math> $n \\ge 5$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>. We show that <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline7.png\" /> <jats:tex-math> $\\mathrm {A}_n$ </jats:tex-math> </jats:alternatives> </jats:inline-formula> is determined up to isomorphism by <jats:inline-formula> <jats:alternatives> <jats:inline-graphic xmlns:xlink=\"http://www.w3.org/1999/xlink\" mime-subtype=\"png\" xlink:href=\"S0004972723001429_inline8.png\" /> <jats:tex-math> $\\operatorname {cod}(\\mathrm {A}_n)$ </jats:tex-math> </jats:alternatives> </jats:inline-formula>.","PeriodicalId":50720,"journal":{"name":"Bulletin of the Australian Mathematical Society","volume":"31 1","pages":""},"PeriodicalIF":0.6000,"publicationDate":"2024-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Bulletin of the Australian Mathematical Society","FirstCategoryId":"100","ListUrlMain":"https://doi.org/10.1017/s0004972723001429","RegionNum":4,"RegionCategory":"数学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATHEMATICS","Score":null,"Total":0}
引用次数: 0
Abstract
Let G be a finite group and $\mathrm {Irr}(G)$ the set of all irreducible complex characters of G. Define the codegree of $\chi \in \mathrm {Irr}(G)$ as $\mathrm {cod}(\chi ):={|G:\mathrm {ker}(\chi ) |}/{\chi (1)}$ and let $\mathrm {cod}(G):=\{\mathrm {cod}(\chi ) \mid \chi \in \mathrm {Irr}(G)\}$ be the codegree set of G. Let $\mathrm {A}_n$ be an alternating group of degree $n \ge 5$ . We show that $\mathrm {A}_n$ is determined up to isomorphism by $\operatorname {cod}(\mathrm {A}_n)$ .
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Bulletin of the Australian Mathematical Society aims at quick publication of original research in all branches of mathematics. Papers are accepted only after peer review but editorial decisions on acceptance or otherwise are taken quickly, normally within a month of receipt of the paper. The Bulletin concentrates on presenting new and interesting results in a clear and attractive way.
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